Ion implantation is a standard technique for introducing impurities into a workpiece. A desired impurity material is ionized in an ion source, the ions are accelerated to form an ion beam of prescribed energy, and the ion beam is directed at the surface of the workpiece. The energetic ions in the ion beam penetrate into the bulk of the workpiece material and are embedded into the crystalline lattice of the workpiece material.
Insulating workpieces (or workpieces with insulating properties) provide unique challenges during plasma processing. For example, it may be difficult to electrostatically clamp or manage charge buildup on insulating workpieces. Charge buildup can lead to variations in implant or deposition depth or can lead to repeatability problems with thin workpieces. Charge buildup also can prevent some ion penetration when processing thicker insulating workpieces. Some insulating material will charge negatively during ion implantation, which will impede or decrease the effective or desired implant energy. In some embodiments, this negative charge will prevent any ion implantation. What is needed is a new method of plasma processing for insulating workpieces or, more particularly, for workpieces to form a coating.